A conventional quick locker for a screw rod contains a first clamp element and a second clamp element which are connected by a C flexible retainer, hence a first press extension of the first clamp element and a second press extension of the second clamp element are pressed so that the quick locker clamp on a locking position of the screw rod, and first threads of a first semicircular groove of the first clamp element and second threads of a second semicircular groove of the second clamp element screw with outer threads of the screw rod, thus locking the quick locker on the screw rod.
However, a first clamping portion of the first clamp element and a second clamping portion of the second clamp element are semicircular, so it is not easy for a wrench or other clamping tools to rotate the quick locker.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.